The present invention relates generally to vessel harvesting and in particular to an improvement over existing endoscopic vessel harvesting techniques and devices.
Endoscopic harvesting of vessels is well known in the surgical field and has been the subject of a great deal of recent technological advancement. Typically, the harvesting of vessels is performed so that the vessels can then be used for procedures such as Cardio Artery Bypass Grafting (CABG). In this procedure the saphenous veins of the legs are harvested for subsequent use in the CABG surgery.
Devices and methods for such vessel harvesting are well known and have been described in numerous publications including U.S. Pat. No. 5,667,480 issued Sep. 16, 1997 and U.S. Pat. No. 5,722,934 issued Mar. 3, 1998 to Knight et al, both of which are incorporated herein by their reference. The devices and methods of these patents are briefly described below and are shown in FIGS. 1 and 2.
In the traditional harvesting devices as shown in FIG. 1, there is provided a hollow shaft 12 connected to a concave head piece 16 located at the distal end of the shaft which provides a workspace 18. An endoscope 5 with a distal end 6 is typically inserted in the shaft so that the surgeon may view workspace. The edge of the head piece 17 is used for dissecting the vessel from the surrounding tissue as shown in FIG. 2. The device may also have guide rails located on the underside of the device which allow for the entry of other devices such as dissectors, ligation tools, and cutting tools into the workspace.
The traditional method for removal of a vessel section as shown in FIG. 2 is as follows. Initially an incision 3 is made and the vessel 7 is located. Then, the vessel 7 is dissected from the surrounding tissue using the leading edge of the head piece 16 of the device 10 to separate the tissue from the vessel 7. At this time there is sufficient workspace 18 created around the vessel 7 so that other instruments can be inserted into the incision 3 via the guide rails located on the underside of the device. These instruments include ligation tools for securing side branch vessels, a vessel dissector for performing a more complete dissection of the vessel which is to be removed, and laproscopic scissors for the transection of both the side branch vessels 9 and the vessel 9 which is to be removed.
Of the known devices and methods for removal of vessels there remains one constant problem. The problem is that to perform each an every one of the side branch ligation and transactions, extra tools must be inserted along the guide rails of the device through the original incision. Often times this means that to perform a single transection of a side branch vessel three tools must be inserted in succession into the body. The various tools include, a dissector to dissect the side branch from the surrounding tissue, a ligation tool to clamp the side branch vessel and the vessel to be removed, and a cutting tool to perform the transection. Additionally, the harvesting device remains in the body throughout the procedure.
This requirement of inserting the tools in succession and exchanging one tool for another to perform each step of the operation requires extra time, this in turn can be a drain on the individual surgeons resources. Further, because of this increased amount of time, which the surgeon requires to perform the operation, the stress on the patient is increased. Minimization of patient stress is naturally a concern during any surgical procedure. Therefore, the elimination of some or all of the time extending tool exchanges would greatly benefit not only the patient but the surgeon as well.
The present invention is directed to solving the shortcomings of known vessel harvesting devices, by providing a superior vessel harvesting device, promoting efficient removal of vessels, and limiting the stress on patients. The objects of the present invention are the minimization of the tool exchanges, increased efficiency of operation, minimization of patient stress, and increased ease of the overall harvest operation. The present invention pertains to a device having a means for capturing side branch vessels so that they may be ligated and transected. The present invention provides for in a single instrument the features that traditionally required at least two and often more instruments. Currently, these several instruments are introduced through the same incision, and held together with the endoscopic portions approximately parallel. This is often referred to as xe2x80x9csword fightingxe2x80x9d due to the complications associated with performing the procedure. xe2x80x9cSword fightingxe2x80x9d often traumatizes the incision and the internal tissue structures. The effect of requiring two hands to perform the procedure coupled with fact that operators may include both surgeons and surgical assistants of varying skill highlights the advantages of developing a single device to perform these varied tasks. Thus, a single instrument combining the functions of dissection, retraction, visualization of a vessel within a workspace, and division of the vessel, would greatly benefit both the patient and the operator.
Accordingly, a vessel harvesting device is provided. The vessel harvesting device comprises a shaft having a lumen for accepting an endoscope therethrough, a t head piece connected to the distal end of the shaft. The headpiece creates a workspace which can be viewed through an endoscope that is inserted through the shaft. A vessel capturing means, operable within the workspace between an open and a closed position to capture side branch vessels. The vessel capturing means is preferably comprised of a flexible upper jaw and a rigid lower jaw. The device preferably has a handle which is connected to the proximal end of the hollow shaft. The handle allows the operator to manipulate the device.
The vessel capturing means can be opened and closed at the discretion of the operator via an actuating means. Preferably, the vessel capturing means is opened when a tube which surrounds the flexible and rigid portions of the jaw and is retracted towards the proximal end of the device. To close the vessel capturing means, the tube is slid towards the distal end of the device. Upon the dissection of a side branch vessel the operator opens the vessel capturing means allowing the operator to place the side branch vessel inside of the vessel capturing means, effectively capturing the side branch vessel. Upon capture of the side branch vessel, the vessel capturing means is closed.
The vessel capturing means can be fitted with ligation and transection means. This allows the operator to capture, ligate, and transect a side branch vessel without requiring of other instruments to be inserted into the workspace. The transection means is preferably a knife edge housed in the lower jaw. The knife edge is drawn towards the proximal end of the device by an actuation means to cut a side branch vessel.
The ligation means is preferably a bi-polar electrode arrangement wherein the tube, which closes the jaws, is used as one electrode and a raised portion of the cutting means is the other electrode. Upon capture of a side branch vessel in the movable jaw, the side branch vessel is ligated by energizing the electrodes with RF energy.
Also provided is a method of removing a vessel utilizing the above-described device. The first step in such a method involves locating the vessel to be removed. Next an incision is made in the patient to expose the vessel and the harvesting device is inserted through the incision in the usual manner. The head of the device is used to dissect the vessel to be removed from the surrounding tissue. Upon dissection, side branch vessels are exposed. The vessel harvesting means, located on the distal end of the device is then placed over the side branch vessel. The side branch vessels are then captured, the vessel capturing means is closed and the side branch vessel is held in place by the now closed vessel capturing means. The side branch vessels are then ligated and transected by the ligation and transection means which are located in the vessel capturing means. The ligation means is preferably a pair of bi-polar electrodes which are energized with RF energy upon capture of the side branch vessels. The ligation means is preferably a knife housed in a lower jaw of the vessel capturing means. The knife transects the ligated side branch vessel upon being drawn in the proximal direction by the user via the actuating means.
This use of the vessel capturing means and the ligation and transection means located therein limits the number of tools which must be inserted into the incision. Further, by having the ligation and transection means located in the vessel capturing means, the procedure is more easily performed, and with a minimum of stress to the patient and in a decreased amount of time.